Musical instrument string



Aug. 4, 1936- c B. GRAY 2,049,770

MUSICAL INSTRUMENT STRING Filed Oct. 16, 1935 INVENTOR CHHRLES B. GRH).

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ATTORNEY Patented Aug. 4, 1936 UNITED STATES PATENT OFFlQE 1 12 Claims.

My invention relates to musical instrument strings and it has for anobject to provide apparatus of this character having improved physicalproperties.

In my application, Serial No. 690,455, filed Sept. 21, 1933, for Musicalinstrument string, are

disclosed and claimed several improved features relating to musicalinstrument strings, and the present application is in part acontinuation of certain subject matter thereof, particularly withrespect to the composite type of string having external loading.Accordingly, a further object of my invention is to provide a stringcomprising a central metallic core or reinforcement structure and atubular covering of coating medium saturating and incorporating fabricmaterial t:- gether with an external metallic loading wire Wrappedthereon.

Another object of my invention is to provide a musical instrument stringincluding a plurality of metallic strands to afford strength andflexibility.

These and other objects are effected by my invention as will be apparentfrom the following description and claims taken in connection with theaccompanying drawing, in which:

Fig. 1 is a view, partly in elevation and partly in section, and showinga loaded composite string with a kinked wire central reinforcement orcore structure; I

Figs. 2 to 5, inclusive, are views showing modified forms of corestructures or reinforcements;

Figs. 6 to 10, inclusive, show further modified forms wherein the corestructures include central core elements;

Fig. 11 is a View representative of any of the foregoing types withoutthe silk wrapping; and

Figs. 12 to 15, inclusive are views showing strings consisting ofstrands of wires twisted together.

All of the views are enlarged to bring out clearly features of thestrings and to aid in a ready understanding of the invention; and parts,such as the kinked reinforcement of Fig. 1, are exaggerated to showplainly the kinking and the like.

In Fig. l, the string includes a kinked wire reinforcement in, which iswrapped with fabric II arranged at a large helix angle. The central wirewith its fabric wrapping is saturated with a coating medium, such asinsulating varnish of the baking type, which gives the desiredproperties of hardness, flexibility, moisture-proofness and resonanceand which incorporates the fabric and joinsthe latter to thereinforcement so that, as pointed out in my application aforesaid, a

unitary and resonant string structure results. The large helix angle ofthe fabric wrapping provides for fibers thereof being effective to carrypart of the string tension. Preferably the cover. ing just described isenclosed by a layer of silk l2 and suitable loading wire it is wrappedon the silk.

The reinforcement or core structure It of Fig.' 1 has a succession ofvery small kinks or corrugations to give endwise elasticity to thestring, making tuning easier, ten-ding to maintain the tuned condition,and promoting freer or easier vibration. The reinforcement is extendedto the right in Fig. l to show features of the kinking. If tangent linesa. and b touching the crests of the 15 kinks are drawn, it will be notedthat the dis tance 0 between such lines is only slightly greater thanthewire diameter d, with the result that the string axis 6 is wellwithin the structure of the wire throughout its length. In actualpractice, the kinks are so small as to be hardly perceptible, the wireis practically and op-eratively straight, and wire larger than standardis not required on account of kinking. Kinking may result in thedistance 0 being of the order of 10 or 29% greater than the diameter d.

In Fig. 2, there is shown a string having a central reinforcement orcore structure Illa including a plurality of wires Hi twisted together.

This type of core structure provides adequate strength and flexibility.The reinforcement or core structure may be made even more flexible forlarge strings by making it of a plurality of twisted strands Ma, asshown in Fig. 3a, each strand including a plurality of small wires I41). Fig. 5 shows a core structure lfib including a plurality of braidedwires l5.

Fig. 4 shows a construction wherein the reinforcement consists of asingle straight wire I 00.

Figs. 6 to 10, inclusive, show further modified forms of centralreinforcements or core structures. In Figs. 6 and '7, the core structureHid includes a plurality of wire strands l6 twisted about a wire coreelement ll, each strand I6 consisting of a plurality of twisted wires IGo. In Fig. 8, the core element Ila of the reinforcement or coreconstruction includes a plurality of wires llb twisted together; and, inFig. 8a, the core element is made up of a plurality of twisted strandsI'lc, each strand including a plurality of Wires I'ld. In Figs. 9 and10, the core element He is made of fibrous material, for example, hemp.

As shown in Fig. 11, any of the forms so far described may have the silkwrapping omitted, the

loading wire [3 being wrapped directly on the tubular cover comprised bythe coating medium incorporating the fabric material.

Figs. 12, 13 and 14 show strings without the tubular covering andloading, as already described, the strings in these views being similarto the core structures or reinforcements of Figs. 6, 8, and 10,respectively. The string in Fig. 12 includes a plurality of strands l8wound about a central core wire 19. In Fig. 13, the core wire or elementis made up of a plurality of twisted wires Mia; and, in Fig. 14, afabric core element 19b is employed. Fig. shows a string of the types ofFigs. 12, 13 and 14 with a loading wire 20 wrapped thereon.

From the foregoing, it will be apparent that I have provided a compositeand unitary type of string with external loading which may beconstructed to suit a wide field of application to musical instrumentsof the stringed type. The core structure or reinforcement may becomprised by a single wire or by a plurality of wires; one or morelayers of fabric may be used, the fabric being incorporated in thecoating medium and being so arranged that its fibers are effective tocarry part of the string tension; and any suitable loading wire may beused. Endwise elasticity is afforded by the kinked reinforcement or bythe twisted types, and the twisted type of construction makes possible adesired combination of strength and flexibility. The construction havinga fibrous core element or center is advantageous in that, for a givenamount of wire, the reinforcement of a string may be made of largerdiameter, with the result that, due to the location of the wiresrelatively close to the string surface, likelihood of the reinforcementcutting the fabric wrapping is reduced. Also a reinforcement with fibercenter makes possible a larger string diameter for a given amount ofWire. Furthermore, features of the twisted types of reinforcements orcore structures with core elements or centers may be used without thefabric covering in the construction of metallic strings of desired size,flexibility and strength.

What I claim is:

1. In a musical instrument string including an inner metallic corestructure, a tubular and cylindrical cover adhering to the corestructure, said cover including a body of tough, flexible andmoisture-proof coating medium incorporating fabric material and adheringto the latter and to the core structure, said fabric materialencompassing the core structure and including fibers -or strandsextending sufliciently longitudinally of the string to carry part of thestring tension, and a helical wrapping of loading wire encompassing thecover.

2. The combination as claimed in claim 1 with a layer of silk betweenthe cover and the loading wire.

3. The combination as claimed in claim 1 wherein the metallic corestructure includes a. plurality of strands of wire.

4. The combination as claimed in claim '1 wherein the metallic corestructure is comprised by a single wire having a succession of kinkswhich are so small that the string axis under all conditions is entirelywithin the structure of the wire.

5. In a musical instrument string comprising a core structure includinga central core element with a plurality of metallic strands woundhelically about the core element and a tubular and cylindrical coveradhering to the core structure, said cover including a body of tough,flexible and moisture-proof coating medium incorporating fabric materialand adhering to the latter and to the core structure and filling allvoids and interstices to secure uniformity of string section and thefabric material being so disposed that fibers thereof are effective tocarry part of the string tension.

6. The combination as claimed in claim 5 wherein the central coreelement of the core structure is comprised by fabric material.

7. The combination as claimed in claim 5 wherein the central coreelement of the core structure is comprised by wire.

8. The combination as claimed in claim 5 with a helical wrapping ofloading wire.

9. A musical instrument string comprising a core element and a pluralityof strands of wire twisted helically about the core element.

10. The combination as claimed in claim 9 wherein the core element iscomprised by fabric material.

11. The combination as claimed in claim 9 wherein the core element ismetallic.

12. The combination as claimed in claim 9 wherein the core element iscomprised by a plurality of wires.

CHAS. B. GRAY.

